Hi Stephanie, I may have information on people called Thomas Allan but all my birth, marriage and death records for Lesmahagow are on micro film and my reader is broken. I do have a couple of grave inscriptions for Thomas Allan's, buried at Lesmahagow Churchyard which I have listed below:
Thomas Allan, Tenant of Brounhills, died 18th January 1814, aged 54, wife Marion Peacock, died 16th July 1841, aged 79, daughter Marion, infant, daughter Janet, died 9th February 1815, aged 20.
Thomas Allan, late of Smith Hill, died 3rd October, 1815, aged 43 or 45, daughter Mary, died 24th May 1830, aged 17.
Hope this is a help to you. When I get a new reader, I'll look for Thomas Allan's and get back to you if I find Any.